About 18.9 million homes in the US stood empty during the second quarter as surging foreclosures helped push ownership to the lowest level in a decade.

The number of vacant properties, including foreclosures, residences for sale and vacation homes, rose from 18.6 million in the year-earlier quarter, the US Census Bureau said in a report today. The ownership rate, meaning households that own their own residence, was 66.9 per cent, the lowest since 1999.

The data are astonishing:

Foreclosures are included in a part of the Census Bureau report that also tracks vacant properties under renovation or tied up in legal proceedings. There were 3.7 million such empty homes in the second quarter, up from 3.5 million in the year earlier period, the report said.

A record 4.6 per cent of US mortgages were in foreclosure in the first three months of 2010, according to a May 19 report by the Mortgage Bankers Association. The combined share of foreclosures and home loan delinquencies was 14 per cent, or about one in every seven US mortgages.

This last quote goes a long way to explaining why the real housing professionals, i.e. Bruce Norris of Riverside, have been predicting a rate of foreclosure (ROF) for California between 13.5-17.5%.

To put that in context, the worst ROF was the last downturn in the 90’s where it was 6%.